U.S. Patent Application Publication No. 2013/0273781 A1, published Oct. 17, 2013, discloses an electrical connector including a connector housing and a plurality of leadframe assemblies supported by the connector housing. U.S. Patent Application Publication No. 2013/0273781 A1, published Oct. 17, 2013, is hereby incorporated by reference as if set forth in its entirety herein. As illustrated in FIG. 1, and as disclosed in U.S. Patent Application Publication No. 2013/0273781 A1, each leadframe assembly 20 includes a leadframe housing 22, a plurality of electrical signal contacts 24 supported by the leadframe housing 22, and an electrically conductive ground plate 26 supported by the leadframe housing 22. The ground plate 26 defines a plurality of ground mating ends 28 and ground mounting ends 30. Alternatively, the ground mating ends 28 and ground mounting ends 30 can be defined respective pluralities of individual ground contacts. The ground mating ends 28 are aligned with mating ends 32 of the respective electrical signal contacts 24 of the leadframe assembly 20 along a transverse direction and the ground mounting ends 30 are aligned with mounting ends 34 of the electrical signal contacts 24 of the leadframe assembly 20 along a longitudinal direction L that is perpendicular to the transverse direction T. The longitudinal direction L can define a column direction at the mounting interface of the electrical connector. The leadframe assemblies 20 are spaced from each other along a row direction, which is defined by a lateral direction A that is perpendicular to each of the longitudinal direction L and the transverse direction T. The leadframe housing 22 can be overmolded onto the electrical signal contacts 24 so as to define an insert molded leadframe assembly (IMLA). The ground plate 26 can be embossed so as to define a plurality of ribs 36 that extend between respective ones of the ground mounting ends and the ground mating ends. It is desired to maintain alignment of the leadframe assemblies 20 with respect to each other, such that the all mounting ends 34 and 30 are aligned with predetermined mounting locations of an underlying substrate to which the electrical connector is configured to be mounted. In one example, the mounting ends can be configured as press-fit tails, and the mounting locations can be configured as openings in the substrate that are configured to receive the press-fit tails.